Putting a custom designed electronic lock on your space seems like a geek right of passage. For our latest workspace, we decided to skip the boring numbered keypad and build a custom RGB backlit keypad powered by an Arduino. Instead of typing in numbers, your password is a unique set of colors. In today’s How-To, we’ll show you how to build your own and give you the code to make it all work.

The basic design for the RGB keypad came from [JMG]’s Arduino based Monome clone. He used an Arduino, and multiplexed RGB LEDs with some digital potentiometers to create a color mixing keypad. Since we couldn’t fit the complete 4×4 keypad into a standard 2 gang wall box, we chopped the design down to a 2×4 matrix. This cuts down significantly on the cost to build the keypad and makes the code that much easier to digest.